Rename MemorySourceAccessor::File::Directory::{contents -> entries}

This matches the "NAR Listing" JSON format, and also helps distinguish
from regular file contents.

Why we want to match that will become clear in the next comments, when
we will in fact use (variations of) this data type for NAR listings.

Author: Ericson2314

src/libstore-tests/references.cc

@@ -99,7 +99,7 @@ TEST(references, scanForReferencesDeep)
     // Create an in-memory file system with various reference patterns
     auto accessor = make_ref<MemorySourceAccessor>();
     accessor->root = File::Directory{
-        .contents{
+        .entries{
             {
                 // file1.txt: contains hash1
                 "file1.txt",
@@ -125,7 +125,7 @@ TEST(references, scanForReferencesDeep)
                 // subdir: a subdirectory
                 "subdir",
                 File::Directory{
-                    .contents{
+                    .entries{
                         {
                             // subdir/file4.txt: contains hash1 again
                             "file4.txt",

src/libutil-tests/git.cc

@@ -230,7 +230,7 @@ TEST_F(GitTest, both_roundrip)
 
     auto files = make_ref<MemorySourceAccessor>();
     files->root = File::Directory{
-        .contents{
+        .entries{
             {
                 "foo",
                 File::Regular{
@@ -240,7 +240,7 @@ TEST_F(GitTest, both_roundrip)
             {
                 "bar",
                 File::Directory{
-                    .contents =
+                    .entries =
                         {
                             {
                                 "baz",

src/libutil/include/nix/util/memory-source-accessor.hh

@@ -35,7 +35,7 @@ struct MemorySourceAccessor : virtual SourceAccessor
         {
             using Name = std::string;
 
-            std::map<Name, File, std::less<>> contents;
+            std::map<Name, File, std::less<>> entries;
 
             bool operator==(const Directory &) const noexcept;
             // TODO libc++ 16 (used by darwin) missing `std::map::operator <=>`, can't do yet.
@@ -95,7 +95,7 @@ inline bool MemorySourceAccessor::File::Directory::operator==(
 inline bool
 MemorySourceAccessor::File::Directory::operator<(const MemorySourceAccessor::File::Directory & other) const noexcept
 {
-    return contents < other.contents;
+    return entries < other.entries;
 }
 
 inline bool MemorySourceAccessor::File::operator==(const MemorySourceAccessor::File &) const noexcept = default;

src/libutil/memory-source-accessor.cc

@@ -29,13 +29,13 @@ MemorySourceAccessor::File * MemorySourceAccessor::open(const CanonPath & path,
             return nullptr;
         auto & curDir = *curDirP;
 
-        auto i = curDir.contents.find(name);
-        if (i == curDir.contents.end()) {
+        auto i = curDir.entries.find(name);
+        if (i == curDir.entries.end()) {
             if (!create)
                 return nullptr;
             else {
                 newF = true;
-                i = curDir.contents.insert(
+                i = curDir.entries.insert(
                     i,
                     {
                         std::string{name},
@@ -106,7 +106,7 @@ MemorySourceAccessor::DirEntries MemorySourceAccessor::readDirectory(const Canon
         throw Error("file '%s' does not exist", path);
     if (auto * d = std::get_if<File::Directory>(&f->raw)) {
         DirEntries res;
-        for (auto & [name, file] : d->contents)
+        for (auto & [name, file] : d->entries)
             res.insert_or_assign(name, file.lstat().type);
         return res;
     } else